| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an LED drive circuit or the like capable of reducing a flicker occurring when an LED load is lighting-controlled in low brightness, due to the fluctuation of an AC power supply. <P>SOLUTION: An LED drive circuit connectable to a phase control type dimmer, in which a phase-controlled AC voltage is inputted from the phase control type dimmer and an LED load is driven by a voltage obtained by rectifying the inputted AC voltage, is configured to comprise a first phase angle detection part for detecting a phase angle in a current cycle, a second phase angle detection part for detecting a phase angle preceding by at least one cycle the current cycle, a bias part for creating a detection signal by adding a prescribed delay time to the phase angle obtained by averaging the phase angle detected by the first phase angle detection part and the phase angle detected by the second phase angle detection part, and a drive part for starting to supply an electric current to the LED load at timing based on the detection signal created by the bias part. <P>COPYRIGHT: (C)2012,JPO&INPIT |
